RESUMO
Emerging evidence suggests brain white matter alterations in adolescents with early-onset psychosis (EOP; age of onset <18 years). However, as neuroimaging methods vary and sample sizes are modest, results remain inconclusive. Using harmonized data processing protocols and a mega-analytic approach, we compared white matter microstructure in EOP and healthy controls using diffusion tensor imaging (DTI). Our sample included 321 adolescents with EOP (median age = 16.6 years, interquartile range (IQR) = 2.14, 46.4% females) and 265 adolescent healthy controls (median age = 16.2 years, IQR = 2.43, 57.7% females) pooled from nine sites. All sites extracted mean fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for 25 white matter regions of interest per participant. ComBat harmonization was performed for all DTI measures to adjust for scanner differences. Multiple linear regression models were fitted to investigate case-control differences and associations with clinical variables in regional DTI measures. We found widespread lower FA in EOP compared to healthy controls, with the largest effect sizes in the superior longitudinal fasciculus (Cohen's d = 0.37), posterior corona radiata (d = 0.32), and superior fronto-occipital fasciculus (d = 0.31). We also found widespread higher RD and more localized higher MD and AD. We detected significant effects of diagnostic subgroup, sex, and duration of illness, but not medication status. Using the largest EOP DTI sample to date, our findings suggest a profile of widespread white matter microstructure alterations in adolescents with EOP, most prominently in male individuals with early-onset schizophrenia and individuals with a shorter duration of illness.
Assuntos
Transtornos Psicóticos , Esquizofrenia , Substância Branca , Feminino , Humanos , Masculino , Adolescente , Imagem de Tensor de Difusão/métodos , Encéfalo , Esquizofrenia/tratamento farmacológico , AnisotropiaRESUMO
Early-onset psychosis disorders are serious mental disorders arising before the age of 18 years. Here, we investigate the largest neuroimaging dataset, to date, of patients with early-onset psychosis and healthy controls for differences in intracranial and subcortical brain volumes. The sample included 263 patients with early-onset psychosis (mean age: 16.4 ± 1.4 years, mean illness duration: 1.5 ± 1.4 years, 39.2% female) and 359 healthy controls (mean age: 15.9 ± 1.7 years, 45.4% female) with magnetic resonance imaging data, pooled from 11 clinical cohorts. Patients were diagnosed with early-onset schizophrenia (n = 183), affective psychosis (n = 39), or other psychotic disorders (n = 41). We used linear mixed-effects models to investigate differences in intracranial and subcortical volumes across the patient sample, diagnostic subgroup and antipsychotic medication, relative to controls. We observed significantly lower intracranial (Cohen's d = -0.39) and hippocampal (d = -0.25) volumes, and higher caudate (d = 0.25) and pallidum (d = 0.24) volumes in patients relative to controls. Intracranial volume was lower in both early-onset schizophrenia (d = -0.34) and affective psychosis (d = -0.42), and early-onset schizophrenia showed lower hippocampal (d = -0.24) and higher pallidum (d = 0.29) volumes. Patients who were currently treated with antipsychotic medication (n = 193) had significantly lower intracranial volume (d = -0.42). The findings demonstrate a similar pattern of brain alterations in early-onset psychosis as previously reported in adult psychosis, but with notably low intracranial volume. The low intracranial volume suggests disrupted neurodevelopment in adolescent early-onset psychosis.
Assuntos
Desenvolvimento do Adolescente/fisiologia , Transtornos Psicóticos Afetivos/patologia , Encéfalo/patologia , Transtornos Psicóticos/patologia , Esquizofrenia/patologia , Adolescente , Transtornos Psicóticos Afetivos/diagnóstico por imagem , Idade de Início , Encéfalo/diagnóstico por imagem , Globo Pálido/diagnóstico por imagem , Globo Pálido/patologia , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Transtornos Psicóticos/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagemRESUMO
Objective: To examine cognitive performance, stratified by age and sex, in adolescents with early-onset psychosis (EOP), relative to the healthy adolescent standardized scores for the MATRICS Consensus Cognitive Battery (MCCB). Method: Seventy-one EOP patients (12-18 years) were included in the study. Raw scores of nine MCCB tests were converted into age- and sex-corrected T scores comprising six domains and global cognition (cognitive composite score). Patient performance, relative to the healthy reference group, was examined using one sample t-tests (reference T score mean of 50). Age effects were examined using one-way analyses of variance between three age groups (12-14 years, 15-16 years, 17-18 years). Sex differences were examined using independent samples t tests. Results: The patients performed significantly worse than the healthy reference group in all MCCB domains, with a global deficit of -1.6 SD below the reference. Across the domains, the impairments varied from -1.4 SD in speed of processing to -0.6 SD in visual learning and reasoning and problem-solving. Significant age effects were found in speed of processing, attention/vigilance, reasoning and problem-solving, and global cognition. The oldest age group showed largest impairments relative to the age- and sex-corrected reference. Female patients had a significantly higher mean T score in verbal learning compared to males. Conclusions: This study provides a MCCB performance profile in EOP, stratified by age and sex, relative to adolescent standardized scores. The results can be used to improve cognitive remediation strategies and subsequent functional outcome, in adolescent EOP and related clinical populations. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Assuntos
Disfunção Cognitiva/fisiopatologia , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adolescente , Fatores Etários , Idade de Início , Atenção , Criança , Cognição , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Memória de Curto Prazo , Testes Neuropsicológicos , Transtornos Psicóticos/psicologia , Padrões de Referência , Caracteres Sexuais , Fatores Sexuais , Aprendizagem VerbalRESUMO
Background: Early-onset psychosis (EOP) is among the leading causes of disease burden in adolescents. Negative symptoms and cognitive deficits predicts poorer functional outcome. A better understanding of the association between negative symptoms and cognitive impairment may inform theories on underlying mechanisms and elucidate targets for development of new treatments. Two domains of negative symptoms have been described in adult patients with schizophrenia: apathy and diminished expression, however, the factorial structure of negative symptoms has not been investigated in EOP. We aimed to explore the factorial structure of negative symptoms and investigate associations between cognitive performance and negative symptom domains in adolescents with EOP. We hypothesized that (1) two negative symptom factors would be identifiable, and that (2) diminished expression would be more strongly associated with cognitive performance, similar to adult psychosis patients. Methods: Adolescent patients with non-affective EOP (n = 169) were included from three cohorts: Youth-TOP, Norway (n = 45), Early-Onset Study, Norway (n = 27) and Adolescent Schizophrenia Study, Mexico (n = 97). An exploratory factor analysis was performed to investigate the underlying structure of negative symptoms (measured with the Positive and Negative Syndrome Scale (PANSS)). Factor-models were further assessed using confirmatory factor analyses. Associations between negative symptom domains and six cognitive domains were assessed using multiple linear regression models controlling for age, sex and cohort. The neurocognitive domains from the MATRICS Consensus Cognitive Battery included: speed of processing, attention, working memory, verbal learning, visual learning, and reasoning and problem solving. Results: The exploratory factor analysis of PANSS negative symptoms suggested retaining only a single factor, but a forced two factor solution corroborated previously described factors of apathy and diminished expression in adult-onset schizophrenia. Results from confirmatory factor analysis indicated a better fit for the two-factor model than for the one-factor model. For both negative symptom domains, negative symptom scores were inversely associated with verbal learning scores. Conclusion: The results support the presence of two domains of negative symptoms in EOP; apathy and diminished expression. Future studies on negative symptoms in EOP should examine putative differential effects of these symptom domains. For both domains, negative symptom scores were significantly inversely associated with verbal learning.
RESUMO
It is suggested that neurodevelopmental abnormalities are involved in the disease mechanisms of psychotic disorders. Although cellular adhesion molecules (CAMs) participate in neurodevelopment, modulate blood-brain barrier permeability, and facilitate leukocyte migration, findings concerning their systemic levels in adults with psychosis are inconsistent. We examined plasma levels and mRNA expression in peripheral blood mononuclear cells (PBMCs) of selected CAMs in adolescents with early-onset psychosis (EOP) aged 12-18 years (n = 37) and age-matched healthy controls (HC) (n = 68). EOP patients exhibited significantly lower circulating levels of soluble platelet selectin (~-22%) and soluble vascular cell adhesion molecule-1 (~-14%) than HC. We found no significant associations with symptom severity. PSEL mRNA expression was increased in PBMCs of patients and significantly negatively correlated to duration of illness. These findings suggest a role for CAMs in the pathophysiology of psychotic disorders.
RESUMO
White matter abnormalities are well-established in adult patients with psychosis. Less is known about abnormalities in the rarely occurring adolescent early onset psychosis (EOP). In particular, whether antipsychotic medication might impact white matter microstructure is not known. Using 3T diffusion weighted imaging, we investigated differences in white matter microstructure and the impact of antipsychotic medication status in medicated (n = 11) and unmedicated (n = 11) EOP patients relative to healthy controls (n = 33), aged between 12-18 years. Using Tract-based Spatial Statistics, we calculate case-control differences in scalar diffusion measures, i.e. fractional anisotropy (FA), axial diffusion (AD) and radial diffusion (RD), and investigated their association with antipsychotic medication in patients. We found significantly lower FA in the left genu of the corpus callosum, the left anterior corona radiata (ACR) and the right superior longitudinal fasciculus in EOP patients relative to healthy controls. AD values were also lower in the left ACR, largely overlapping with the FA findings. Mean FA in the left ACR was significantly associated with antipsychotic medication status (Cohen's d = 1.37, 95% CI [0.01, 2.68], p = 0.008), showing higher FA values in medicated compared to unmedicated EOP patients. The present study is the first to link antipsychotic medication status to altered regional FA in the left ACR, a region hypothesized to contribute to the etiology of psychosis. Replications are warranted to draw firm conclusions about putatively enhancing effects of antipsychotic medication on white matter microstructure in adolescent-onset psychosis.
Assuntos
Antipsicóticos/administração & dosagem , Imagem de Tensor de Difusão , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/tratamento farmacológico , Substância Branca/diagnóstico por imagem , Adolescente , Anisotropia , Criança , Feminino , Humanos , MasculinoRESUMO
Neurocognitive deficits are associated with impaired global functioning and psychotic symptoms. However, whether symptoms can mediate the relationship between neurocognition and global functioning in adolescent psychosis is unclear. Here, we investigated if symptoms assessed with the Positive And Negative Syndrome Scale (PANSS), mediated the relationship between neurocognitive performance and global functioning in adolescents with non-affective early-onset psychotic disorders (EOP). Sixty-one adolescent EOP patients (age 12-18 years) from 2 Norwegian clinical cohorts were included. Linear regression models were applied to investigate associations between neurocognitive domains from the MATRICS Consensus Cognitive Battery (MCCB) and global functioning. PANSS symptoms were analyzed using the Wallwork/Fortgang five-factor model. Using the INDIRECT macro for SPSS, mediation effects were tested using bootstrapping with 95% bias corrected confidence intervals. Verbal learning was positively associated with global functioning (P < 0.001) and negatively associated with the disorganized symptom factor (P = 0.002), controlling for age, sex and cohort. Testing of indirect effects, controlling for age, sex and cohort, showed that the Negative (point estimate = 1.56, 95% CI 0.22, 3.47) and Disorganized (point estimate = 1.24, 95% CI 0.05, 3.69) symptom factors significantly mediated the relationship between verbal learning and global functioning. We found that verbal learning, negative and disorganized symptoms influenced global functioning in adolescents with EOP, while reality-distorted positive symptoms did not. These results suggest that assessing these domains in EOP is helpful for planning treatment and rehabilitation programs focusing on functional outcome.
Assuntos
Testes Neuropsicológicos/normas , Transtornos Psicóticos/diagnóstico , Aprendizagem Verbal/fisiologia , Adolescente , Criança , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: Dyslipidemia and insulin resistance (HOMA-IR) are cardiovascular risk factors prevalent in patients with psychosis. Whether these factors are intrinsic or affected by lifestyle or antipsychotic medication (AP) is unclear. Therefore, we investigated lipid profiles, HOMA-IR, and psychotic phenotypes in patients aged 12-18â¯years with early-onset psychosis (EOP) with and without AP exposure. METHOD: We measured fasting total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), triglycerides (TG), insulin, and glucose in patients with EOP (nâ¯=â¯39) and healthy controls (HC) (nâ¯=â¯66). Diet information was not available. Negative symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). We used univariate analysis of variance to compare TC/HDL-C ratios and TG and HOMA-IR values, controlling for body mass index (BMI) and AP exposure. We assessed the explained variance of having EOP using multiple regression analysis. RESULTS: Patients with and without AP exposure had significantly higher TC/HDL-C (pâ¯=â¯0.003, pâ¯=â¯0.029) and TG values (pâ¯<â¯0.001, pâ¯=â¯0.021) than HC. Significantly increased HOMA-IR scores were found only in AP-exposed patients (pâ¯=â¯0.037). EOP significantly increased the explained variance for TC/HDL-C and TG, but not for HOMA-IR. Patients with a PANSS negative scoreâ¯>â¯21 had significantly higher levels of TG than those with low scores (pâ¯=â¯0.032). CONCLUSION: Our results suggest that lipid alterations predate AP treatment in adolescents with EOP. Higher levels of negative symptoms and AP further increase metabolic risk. The preliminary findings propose that subclinical dyslipidemia may be intrinsic to EOP.
Assuntos
Antipsicóticos , Resistência à Insulina , Transtornos Psicóticos , Adolescente , Antipsicóticos/uso terapêutico , Glicemia , Índice de Massa Corporal , HDL-Colesterol , Humanos , Lipídeos , Transtornos Psicóticos/complicações , Transtornos Psicóticos/tratamento farmacológico , TriglicerídeosRESUMO
OBJECTIVE: Evidence indicates that the pathophysiology of adult psychosis involves immune dysregulation, but its associations with stress are often not considered. The inflammatory cytokine interleukin (IL)-18, which is elevated in adult schizophrenia, is suggested to be sensitive to stress. We compared the associations of IL-18 with cortisol and clinical variables in adolescents with early-onset psychosis (EOP) aged 12-18 years and age-matched healthy controls (HC). METHOD: We measured serum IL-18, IL-18 binding protein (IL-18BP), IL-18 receptor accessory protein (IL-18RAP), IL-18 receptor 1 (IL-18R1) and cortisol, and calculated the IL-18/IL-18BP ratio in patients (nâ¯=â¯31) and HC (nâ¯=â¯60). Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale and depressive symptoms by the Mood and Feelings Questionnaire-Child version (MFQ-C). Bivariate correlation analysis was used to explore relationships between IL-18/IL-18BP ratio and cortisol, depression and other clinical characteristics. Hierarchical multiple linear regression analysis was used to assess their individual contributions to the variance of the IL-18/IL-18BP ratio. RESULTS: Patients had significantly higher IL-18 levels and IL-18/IL-18BP ratios than HC, but similar IL-18BP, IL-18RAP and IL-18R1. Both cortisol (R2 changeâ¯=â¯0.05) and the MFQ-C score (R2 changeâ¯=â¯0.09) contributed significantly to the variance in IL-18/IL-18BP ratios after controlling for confounders. CONCLUSION: We found increased IL-18 system activity in adolescents with EOP. Cortisol and depressive symptoms each contributed to the variance in the IL-18/IL-18BP ratio. Our findings support activation of inflammatory pathways in adolescent psychosis and suggest interactions between stress, inflammation and depressive symptoms in EOP.
Assuntos
Depressão , Hidrocortisona/sangue , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Interleucina-18/sangue , Transtornos Psicóticos , Adolescente , Idade de Início , Estudos de Casos e Controles , Criança , Depressão/sangue , Depressão/imunologia , Depressão/fisiopatologia , Humanos , Subunidade alfa de Receptor de Interleucina-18/sangue , Subunidade beta de Receptor de Interleucina-18/sangue , Estudos Longitudinais , Masculino , Transtornos Psicóticos/sangue , Transtornos Psicóticos/imunologia , Transtornos Psicóticos/fisiopatologiaRESUMO
OBJECTIVE: Patterns of co-occurrence between ADHD, Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD) were examined in a sample of non-referred preschool children. ADHD subtypes and sex differences were also explored. METHOD: Children aged 3.5 years ( n = 1,048) with high scores on ADHD characteristics were recruited from the Norwegian Mother and Child Cohort Study and clinically assessed, including a semi-structured psychiatric interview. RESULTS: In children with ADHD, concurrent ODD was present more often than CD (31% vs. 10%), but having ADHD gave higher increase in the odds of CD than of ODD (ODD: odds ratio [OR] = 6.7, 95% confidence interval [CI] = [4.2, 10.8]; CD: OR = 17.6, 95% CI = [5.9, 52.9]). We found a greater proportion of children having the combined ADHD subtype as well as more severe inattentiveness among children with co-occurring CD compared with ODD. Sex differences were minor. CONCLUSION: There are important differences in co-occurring patterns of ODD and CD in preschool children with ADHD.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/epidemiologia , Transtorno da Conduta/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Pré-Escolar , Estudos de Coortes , Comorbidade , Feminino , Humanos , Masculino , Noruega/epidemiologiaRESUMO
Autism spectrum disorders are often comorbid with other psychiatric symptoms and disorders. However, identifying psychiatric comorbidity in children with autism spectrum disorders is challenging. We explored how a questionnaire, the Child Behavior Check List, agreed with a Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV)-based semi-structured interview, the Kiddie-Schedule for Affective Disorders and Schizophrenia for School-Age Children (Kiddie-SADS). The sample comprised 55 children and adolescents (age 6 to 18 years) with autism spectrum disorders, including the main autism spectrum disorder subgroups and the broad range of cognitive and language functioning. High rate of psychopathology was found both through questionnaire and interview assessment. Using predefined Child Behavior Check List cutoffs, we found good agreement between the Child Behavior Check List and the Kiddie-SADS for identifying attention deficit/hyperactivity disorder, depressive disorders, and oppositional defiant disorder. However, overall the specificity of the Child Behavior Check List was low. The Child Behavior Check List was not useful for identifying anxiety disorders. The Child Behavior Check List may capture core symptoms of autism spectrum disorders as well as comorbid psychopathology, and clinicians should be aware that the Child Behavior Check List may be unspecific when used in children and adolescents with autism spectrum disorders.
Assuntos
Transtornos de Ansiedade/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Transtorno do Espectro Autista/epidemiologia , Lista de Checagem , Transtorno Depressivo/epidemiologia , Transtornos de Tique/epidemiologia , Adolescente , Transtornos de Ansiedade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/diagnóstico , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/epidemiologia , Transtorno do Espectro Autista/diagnóstico , Criança , Estudos de Coortes , Comorbidade , Transtorno Depressivo/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Inquéritos e Questionários , Transtornos de Tique/diagnósticoRESUMO
Familial hypercholesterolemia (FH) is associated with heterogeneity of the onset and severity of coronary heart disease (CHD). In this study, we investigated different low-grade proinflammatory markers and the atheroprotective function of the HDL3 subfraction in FH-patients (n = 13) with identical LDL-receptor mutations and in age- and sex-matched healthy controls (n = 11). Compared with healthy controls, FH-patients had greater gene expressions of the proatherogenic mediators TNF-alpha and IL-8 in circulating peripheral blood mononuclear cells. In addition, they had a higher serum concentration of intercellular adhesion molecule-1 (ICAM-1) and a lower net antioxidant capacity. FH-derived HDL3 with a high level of triglycerides had a reduced capacity to inhibit the release of IL-8 from TNF-alpha-stimulated human umbilical vein endothelial cells (HUVEC) [1.864 mg/L (1.461-2.208 mg/L) vs. 1.466 mg/L (1.225-1.643 mg/L); P < 0.05; median (range)], and a reduced capacity to promote cholesterol efflux from lipid-loaded macrophages [12% (12-14%) vs. 15% (14-18%); P < 0.05; median (range)] compared with HDL3 with a lower triglyceride content. Notably, the degree of inhibition of IL-8 release from HUVEC by HDL3 was correlated with the ability of HDL3 to promote cholesterol efflux (r = -0.80, P = 0.03). In conclusion, compared with healthy controls, FH-patients are characterized by higher levels of low-grade proinflammatory markers, and FH-derived HDL3 with high triglyceride content may be more proatherogenic. These triglyceride rich-HDL3 might be partly responsible for the phenotypic variation among FH-patients with identical LDL-receptor mutations.
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Colesterol/metabolismo , Citocinas/sangue , Hiperlipoproteinemia Tipo II/sangue , Lipoproteínas HDL/sangue , Lipoproteínas HDL/farmacologia , Triglicerídeos/sangue , Adulto , Linhagem Celular Tumoral , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Feminino , Humanos , Hiperlipoproteinemia Tipo II/genética , Interleucina-8/metabolismo , Lipoproteínas HDL3 , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação , Fenótipo , Receptores de LDL/genética , Fator de Necrose Tumoral alfa/farmacologia , Veias UmbilicaisRESUMO
BACKGROUND: The article highlights how environmental factors early in life, in combination with genetic vulnerability, can influence development and partly explain variations in mental health. MATERIAL AND METHOD: A selection of key articles identified on Medline. RESULT: The plasticity of a child's brain makes it particularly susceptible to environmental factors. This provides a significant potential for learning and adaptation, but also causes vulnerability with respect to, for instance, mental illness. There are no studies showing that a specific trauma or strain causes a specific psychological disorder later in life. Nonetheless, recent studies show that certain environmental factors in early life could have a lasting impact on a child's psychosocial behaviour. The article sums up some of these findings. CONCLUSION: Early preventive measures are particularly important in cases where a biological vulnerability occurs. It is equally important to have realistic expectations with respect to the results of the various measures. Not everything can be returned to normalcy, though it is always possible to promote a development potential.
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Desenvolvimento Infantil , Exposição Ambiental , Transtornos Mentais/etiologia , Saúde Mental , Adolescente , Adulto , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiologia , Criança , Transtornos do Comportamento Infantil/etiologia , Transtornos do Comportamento Infantil/genética , Desenvolvimento Infantil/fisiologia , Exposição Ambiental/efeitos adversos , Expressão Gênica , Predisposição Genética para Doença , Humanos , Acontecimentos que Mudam a Vida , Transtornos Mentais/genética , Plasticidade Neuronal/genética , Plasticidade Neuronal/fisiologia , Fatores de Risco , Estresse Psicológico/complicações , Estresse Psicológico/genéticaRESUMO
BACKGROUND: It is well established that an excessive intake of retinol (vitamin A) is toxic; however, it has been > 25 y since the last extensive treatise of case reports on this subject. OBJECTIVE: The objectives were to identify and evaluate all individual cases of retinol toxicity published in the scientific literature that assessed the thresholds and symptoms induced by high intakes of retinol and to compare the toxicity of different physical forms of retinol preparations. DESIGN: We performed a meta-analysis of case reports on toxicity claimed to be induced by intakes of excessive amounts of dietary retinol (ie, retinol and retinyl esters in foods or supplements). Using free text and MESH (medical subheading) strategies in PubMed, we identified 248 articles in the scientific literature. From these initial articles we identified other relevant citations. The final database consisted of 259 cases in which individual data on dose, sex, age, time of exposure, and symptoms are reported. RESULTS: Chronic hypervitaminosis A is induced after daily doses of 2 mg retinol/kg in oil-based preparations for many months or years. In contrast, doses as low as 0.2 mg retinol. kg(-1). d(-1) in water-miscible, emulsified, and solid preparations for only a few weeks caused chronic hypervitaminosis A. Thus, water-miscible, emulsified, and solid preparations of retinol are approximately 10 times as toxic as are oil-based retinol preparations. The safe upper single dose of retinol in oil or liver seems to be approximately 4-6 mg/kg body wt. These thresholds do not vary considerably with age. CONCLUSIONS: The results of the present study indicate that the physical form of retinol supplements is a major determinant of toxicity. The use of water-miscible, emulsified, and solid preparations of retinol should therefore be carefully considered before being used in supplements and fortifications.
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Hipervitaminose A/etiologia , Vitamina A/administração & dosagem , Vitamina A/efeitos adversos , Adolescente , Química Farmacêutica , Criança , Pré-Escolar , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Emulsões , Feminino , Humanos , Hipervitaminose A/prevenção & controle , Lactente , Recém-Nascido , Masculino , Solubilidade , Vitamina D/administração & dosagemRESUMO
AIMS: Familial hypercholesterolaemia (FH) is associated with increased risk of premature atherosclerosis and coronary artery disease (CAD). However, onset of clinically manifested CAD varies widely among patients with heterozygous FH, and we hypothesized that inflammatory mediators such as chemokines could contribute to atherogenesis in these patients. METHODS AND RESULTS: We compared peripheral blood mononuclear cells (PBMCs) from FH patients with an identical mutation with PBMCs from sex- and age-matched healthy controls with respect to spontaneous and oxidized low density lipoprotein (oxLDL)-stimulated release of chemokines. Our main findings were: (1) PBMCs from FH patients spontaneously released significantly higher levels of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and interleukin (IL)-8, and had a significantly lower oxLDL-stimulatory ratio for MIP-1alpha and MIP-1beta than cells from healthy controls. (2) Spontaneous release of these chemokines correlated positively and stimulatory ratio correlated negatively with plasma concentrations of total and LDL cholesterol. (3) Among FH patients, release of MIP-1alpha, MIP-1beta and IL-8 from PBMCs varied with the presence of xanthomas/xanthelasms, smoking and gender. (4) In vitro studies showed that FH serum but not control serum was able to induce enhanced spontaneous release of chemokines in PBMCs from both FH patients and control subjects. CONCLUSIONS: Our data may suggest that a pathophysiological consequence of FH is enhanced chemokine responses, which in turn may promote recruitment and activation of leukocytes within the vessel wall, contributing to atherosclerosis as well as to the different phenotypes in these patients with an identical FH mutation.